[PATCH v3 02/10] PCI: Add additional checks for flr reset

Farhan Ali
2025-09-11T18:33:16Z

If a device is in an error state, then any reads of device registers can
return error value. Add addtional checks to validate if a device is in an
error state before doing an flr reset.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
---
drivers/pci/pci.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4b67d22faf0a..3994fa82df68 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4580,12 +4580,19 @@ EXPORT_SYMBOL_GPL(pcie_flr);
*/
int pcie_reset_flr(struct pci_dev *dev, bool probe)
{
+ u32 reg;
+
if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return -ENOTTY;

if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
return -ENOTTY;

+ if (pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &reg)) {
+ pci_warn(dev, "Device unable to do an FLR\n");
+ return -ENOTTY;
+ }
+
if (probe)
return 0;

--
2.43.0